1. Field of the Invention
The present invention relates to an imaging device, more specifically to an imaging device incorporated in a mobile electronic device such as a mobile phone.
2. Description of the Related Art
In recent years, mobile electronic devices such as mobile phones with an inward-facing camera (sub-camera) in addition to an outward-facing camera (main camera) have been in widespread use. The outward-facing camera is used to capture still images or video clips of ordinary subjects while the inward-facing camera is used to capture still images or video clips of the user himself/herself for, e.g., video conferencing. If two separate imaging units are provided as the inward-facing camera and the outward-facing camera, respectively, the device which includes these cameras increases in size and the production cost of the device also increases. Accordingly, it has been desired to provide an imaging device which is equipped with the inward-facing camera and the outward-facing camera and which is structured to be capable of meeting the demand for miniaturization and cost reduction. For instance, Japanese Unexamined Patent Publication 2007-116361 has proposed an imaging device which is configured to be capable of selectively making light bundle that enters the imaging device from the front of the housing of the imaging device and another light bundle that enters the imaging device from the back of the housing incident on a single image pickup device via a linking-up of a reflector and a light-shielding member which are installed in the housing.
In the type of imaging device such as disclosed in the aforementioned Japanese Unexamined Patent Publication, in which the imaging direction (photographing direction) is switched between two different directions by inserting and removing an insertable optical element into and from an optical path, the insertable optical element is inserted into the target optical path up to the center (optical axis) thereof, and the central position of the image forming area on the imaging surface of the image pickup device does not substantially move regardless of whether or not the imaging direction is switched between the two different directions. Therefore, the amount of movement of the insertable optical element in the inserting/removing direction thereof has needed to be greater than at least the radius from the optical axis of the target light bundle traveling along the optical path. Nevertheless, due to the widespread use of mobile electronic devices, the demand for miniaturization of the imaging device has been increasingly growing.